1 /*
2 * Copyright (C) 2009 Joshua Oreman <oremanj@rwcr.net>.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17 */
18
19 FILE_LICENCE ( GPL2_OR_LATER );
20
21 #include <string.h>
22 #include <gpxe/dhcp.h>
23 #include <gpxe/netdevice.h>
24 #include <undipreload.h>
25 #include <pxeparent.h>
26 #include <realmode.h>
27 #include <pxe_api.h>
28
29 /**
30 * Present cached DHCP packet if it exists
31 */
__weak_impl(get_cached_dhcpack)32 void __weak_impl ( get_cached_dhcpack ) ( void ) {
33 struct undi_device *undi;
34 struct s_PXENV_GET_CACHED_INFO get_cached_info;
35 int rc;
36
37 /* Use preloaded UNDI device to get at PXE entry point */
38 undi = &preloaded_undi;
39 if ( ! undi->entry.segment ) {
40 DBG ( "PXEDHCP no preloaded UNDI device found\n" );
41 return;
42 }
43
44 /* Check that stack is available to get cached info */
45 if ( ! ( undi->flags & UNDI_FL_KEEP_ALL ) ) {
46 DBG ( "PXEDHCP stack was unloaded, no cache available\n" );
47 return;
48 }
49
50 /* Obtain cached DHCP packet */
51 memset ( &get_cached_info, 0, sizeof ( get_cached_info ) );
52 get_cached_info.PacketType = PXENV_PACKET_TYPE_DHCP_ACK;
53
54 if ( ( rc = pxeparent_call ( undi->entry, PXENV_GET_CACHED_INFO,
55 &get_cached_info,
56 sizeof ( get_cached_info ) ) ) != 0 ) {
57 DBG ( "PXEDHCP GET_CACHED_INFO failed: %s\n", strerror ( rc ) );
58 return;
59 }
60
61 DBG ( "PXEDHCP got cached info at %04x:%04x length %d\n",
62 get_cached_info.Buffer.segment, get_cached_info.Buffer.offset,
63 get_cached_info.BufferSize );
64
65 /* Present cached DHCP packet */
66 store_cached_dhcpack ( real_to_user ( get_cached_info.Buffer.segment,
67 get_cached_info.Buffer.offset ),
68 get_cached_info.BufferSize );
69 }
70